CVE-2021-27691
Published: 16 April 2021
Summary
CVE-2021-27691 is a critical-severity OS Command Injection (CWE-78) vulnerability in Tendacn G0 Firmware. Its CVSS base score is 9.8 (Critical).
Operationally, ranked in the top 10.8% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2021-14433
Vulnerability details
Command Injection in Tenda G0 routers with firmware versions v15.11.0.6(9039)_CN and v15.11.0.5(5876)_CN , and Tenda G1 and G3 routers with firmware versions v15.11.0.17(9502)_CN or v15.11.0.16(9024)_CN allows remote attackers to execute arbitrary OS commands via a crafted action/setDebugCfg request. This occurs…
more
because the "formSetDebugCfg" function executes glibc's system function with untrusted input.
- CWE(s)
Related Threats
No named actor attribution yet. ATT&CK technique mapping in progress for this CVE.
Affected Assets
Mitigating Controls
Likely Mitigating Controls AI
Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.
Platform-independent apps typically execute inside a managed runtime or sandbox that restricts direct OS command execution, reducing the ability to exploit OS command injection.
Ongoing control assessments and code testing (static/dynamic analysis, fuzzing) surface memory buffer restriction failures, which are then remediated before release.
Validates inputs to block special elements that would alter OS command execution.
Memory protections (e.g., W^X, ASLR) make exploitation of buffer-boundary violations far harder to turn into code execution.
Detects exploitation attempts that produce memory corruption, crashes, or anomalous behavior.